The generation methods and structure of the multi-scroll chaotic attractors in both the Chua system and the Duffing equation exhibit remarkable similarities, suggesting a potential relationship ...between these two systems. Specifically, the Chua system can be transformed into a Duffing-like equation. In this transformation, the second equation of the Chua system forms the main body of the Duffing equation, while the first and third equations contribute to forming potential wells. Consequently, parameters in the Chua system possess physical meanings corresponding to those in the Duffing equation, enabling us to control the Chua system as if it is a Duffing equation. By adjusting various factors such as damping coefficient, potential difference among potential wells, the shape of the potential wells, asymmetric bias, external driving force and oscillation characteristics of potential wells within Chua system framework, we can successfully obtain controllable multi-scroll chaotic attractors. The Multisim simulation circuit and analog circuit experiments have confirmed the results.
•We can control the Chua system as if it is a Duffing equation.•All parameters in the Chua system have physical meanings corresponding to the Duffing equation.•All parameters of the Chua system can control the scroll number according to their physical meaning.
Research on switchable chaotic systems with a large range of parameters is scarce. To explore the chaotic characteristics of such systems, this paper proposes new switchable methods by modifying the ...nonlinear term in the system, resulting in a chaotic system with different nonlinear terms. The unknown parameters in the nonlinear term exhibit different numerical relationships under various combined conditions, and some parameters may tend towards positive infinity. The chaos characteristics are verified by applying a specific switching method to the unified chaotic system. The pseudo-randomness of the random sequence generated by the dissipative system is verified using the NIST test. Finally, the circuit simulation of the system under various switching conditions is performed by selecting different circuit components and adjusting the resistance values.The switching chaotic system is implemented physically on FPGA and breadboard, and the effectiveness of the system is verified.
Alterations in the dynamical properties of an atomic force microscope microcantilever beam system in tapping mode can appreciably impact its measurement precision. Understanding the influence ...mechanism of dynamic parameter changes on the system's motion characteristics is vital to improve the accuracy of the atomic force microscope in tapping mode (AFM-TM). In this study, we categorize the mathematical model of the AFM-TM microcantilever beam system into systems 1 and 2 based on actual working conditions. Then, we analyze the alterations in the dynamic properties of both systems due to external excitation variations using bifurcation diagrams, phase trajectories, Lyapunov indices, and attraction domains. The numerical simulation results show that when the dimensionless external excitation
< 0.183, the motion state of system 2 is period 1. When
< 0.9, the motion state of system 1 is period 1 motion. Finally, we develop the equivalent circuit model of the AFM-TM microcantilever beam and perform related software simulations, along with practical circuit experiments. Our experimental results indicate that the constructed equivalent circuit can effectively analyze the dynamic characteristics of the AFM-TM microcantilever beam system in the presence of complex external environmental factors. It is observed that the practical circuit simulation attenuates high-frequency signals, resulting in a 31.4% reduction in excitation amplitude compared to numerical simulation results. This provides an essential theoretical foundation for selecting external excitation parameters for AFM-TM cantilever beams and offers a novel method for analyzing the dynamics of micro- and nanomechanical systems, as well as other nonlinear systems.
En este trabajo, se diseñó y desarrolló un simulador que permite realizar estudios mucho más profundos en los generadores eléctricos por vibraciones piezoeléctricas; para ello se partió del ...comportamiento mecánico de un cristal piezoeléctrico sencillo. Se modeló matemáticamente su funcionamiento, obteniendo un circuito eléctrico equivalente al comportamiento mecánico de estos cristales, posteriormente haciendo uso de NI Multisim 14.0, se simuló un sistema cosechador de energía básico. Para obtener datos certeros y observar la eficiencia de la simulación es necesario hacer uso de un cosechador de energía por medio de vibraciones de forma física, por lo que se construyó un dispositivo de almacenamiento de energía mediante piezoeléctricos desarrollado en investigaciones anteriores, a fin de garantizar que sea un buen instrumento de medición para la captura de las variables necesarias. Finalmente se determinó la ecuación que relaciona la fuerza aplicada a los cristales, con la tensión a la salida del cosechador, para así poder aplicar estos datos a las simulaciones desarrolladas, y calcular el porcentaje de error que posee el simulador.
This paper concerns the control problems of an induction motor with chaotic behavior due to the defiance of indirect field oriented control applied with a proportional integral (PI) speed loop. The ...feedbacks predictive control is used to control this chaotic system owing to its simplicity of configuration and implementation. In general, the gain of the predictive control used in the literature is taken as a constant included in an interval, however, in this work, this gain is taken a matrix and Linear matrix inequality is using to calculate this gain. To highlight the efficiency and applicability of the proposed control scheme, simulations and experimental results are presented.
We review the most common topology of multi-level inverters. As is known, the conventional inverters are utilized to create an alternating current (AC) source from a direct current (DC) source. The ...two-level inverter provides various output voltages (Vdc/2) and (−Vdc/2) of the load. It is a successive method, but it makes the harmonic distortion of the output side, Electromagnetic interference (EMI), and high dv/dt. We solve this problem by constructing the sinusoidal voltage waveform. This is achieved by a “multilevel inverter” (MLI). The multilevel inverter creates the output voltage with multiple DC voltages as inputs. Many voltage levels are combined to produce a smoother waveform. During the last decade, the multilevel inverter has become very popular in medium and high-power applications with some advantages, such as the reduced power dissipation of switching elements, low harmonics, and low EMIs. We introduce the information about several multilevel inverters such as the diode-clamped multilevel inverter (DC-MLI), cascaded H-bridge multilevel inverter (CHB-MLI), and flying-capacitor multilevel inverter (FC-MLI) with Power systems CAD (PSCAD) simulation. It is shown that THD is 28.88% in three level FC-MLI while THD is 18.56% in five level topology. Therefore, we can decrease the total harmonic distortion adopting the higher-level topology.
Abstract
Simulation of Charge Sensitive Preamplifier (CSP) to improve Nuclear Pulse detecting Circuit has been carried on Multisim Software. Multisim Software is a great software that creates the ...best user-friendly simulation environment for professors, engineers, and students. We can simulate electronic circuits and build prototypes for Printed Circuit Boards (PCBs). In this paper, we have simulated CSP Circuit in two ways. Firstly, by using a pulsed voltage source. Secondly, by using a waveform generator. We have analyzed the behavior of the CSP Circuit with various rise times. The output waveforms have been observed on the oscilloscope.
Frequency divider circuit is the basic circuit in digital logic circuit. The circuit function is to divide or drop the frequency of the high frequency signal to get the lower frequency signal for a ...given frequency signal by division. On the Multisim software platform, using different design methods, as the foundation of middle scale integration chip 74LS161, design even frequency divider, odd frequency divider circuit and (N- 0.5) frequency divider circuit respectively. Each circuit design principle and method is illustrated and simulated. The results showed that the design is correct and conform to the proposed requirement. Experimental teaching applications based on Multisim software can improve design efficiency and reduce development time of design systems.
Compared with the conventional multi-scroll attractor, the multi-wing butterfly chaotic attractors are easier to design and implement through analog circuitry, thus they has more potential ...applications. In this paper, a chaotic system with four-wing attractors is designed and the dynamic behaviors are analyzed in terms of phase diagram, bifurcation diagram, Lyapunov exponential spectrum and C 0 structural complexity. It is found that each parameter has a large range of intervals that can keep the system in a chaotic state and the generated sequences have sufficient randomness to be well suited for applications in secure communications. Then, the circuit model of the constructed four-wing chaotic system is built with a basic operational amplifier circuit, and the accuracy of the circuit implementation is verified. Finally, a color image compression encryption scheme is designed based on the theory of compressive sensing and DNA dynamic coding. The algorithm is mainly composed of five parts: sparse, compression calculation, 3D projection scrambling, DNA diffusion and plaintext association confusion. The security test results show that the designed scheme not only has superior compression performance and high security, but also has no limitation on the size of the test image.
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